The present invention relates to a laser system and its method of use, and more particularly, to a laser system having two or more laser beams and a concave reflector for use for example in medical applications.
Lasers, and laser systems for use in medical applications are well known. A typical application is the use of laser for microsurgery. In such application, a laser system is attached to an operating microscope. The system comprises two coaxial beams: A first tracking beam, usually at 632 nm. wavelength and is used for aiming the beam to the desired spot on the biological specimen; and an infrared beam, usually at 10.6 microns wavelength for treatment. The laser beams are directed on a path perpendicular to the microscope's field of vision. A flat mirror is typically placed directly before the microscope and is set at 45 degrees with respect to the laser beams. The beams reflected from the flat mirror would then be coaxial with respect to the visual axis of the microscope.
Because the microscope must be adapted for work at several different distances, the laser system must be adapted as well. Heretofore, lenses such as zinc selenide (ZnSe) are used, either singularly or in pairs, to focus the beams of light. The use of the focusing lenses, however, results in several problems. First, power loss in system results from the absorptive property of the material used in the lens. Secondly, because of chromatic aberration, beams impinging the lenses at slightly off axis will not have a common focal point. Finally, the lenses are expensive to manufacture and the material zinc selenide is quite toxic.